Highway crossing signal system



A. E. REID HIGHWAY CROSSING SIGNAL SYSTEM Filed May31/1940 B. onuu mtzuV0006.

INVENTOR BY A. 3.07321 H'ls ATTORNEY Patented Mar. 21, 1944 HIGHWAYCROSSING SIGNAL SYSTEM Arthur E. Reid, Gates, N. Y., assignor to GeneralRailway Signal Company,

Rochester,

Application May 31, 1940, Serial No. 337,993

3 Claims. (Cl. MIL-130) This invention relates in general to highwaycrossing signal systems for intersections of highways with railways, andhas more particular reference to means .for affording protection insituations where sidings enter a main track ad- ,iacent a highwaycrossing.

In a system of the character referred to, in connection with a maintrack on which traflic moves both east and west, it is desirable to givewarning to highway traffic so long as a train is approaching thehighway, but to discontinue the warning when the train is receding fromthe highway. In the event that a train should enter the main track froma siding, at the time a receding train is still on the approach sectionto the highway, with the usual interlocked relays employed in this typeof system, no warning would be given of the train entering from thesiding.

With the above and other objects in View, it is proposed, in accordancewith this invention, to provide means whereby proper protection is givento highway trafiic at all dangerous times.

Further objects, purposes and characteristic features of the presentinvention will appear as the description progresses, reference beingmade to the accompanying drawing, showing solely in a, diagrammaticmanner, and merely for the purpose of illustration, one form ofinvention which the invention can assume. In the drawing:

The'single figure of drawing is a wholly diagrammatic showing of oneembodiment of the present invention. 1

, Referring now to the drawing, there is here represented a stretch ofsingle track, constituted by track rails 4 and 5, across which passes ahighway H. The main track is divided into usual insulated track sectionsby insulating joints 6, whereby to form an east approach section-La westapproach section 2, and a central,

middle, or highway section 3.

Entering the main track is a siding constituted by track rails l and Sand this siding enters the main track adjacent the highway and withinthe west approach section 2, and is controlled by a track switch TS.

The track switch TS is of the spring switch type, of any usual form,wherein the switch can be thrown to either its normal or its reverseposition, by any desired means, although for the purpose of illustrationan operating means in the form of a hand switch stand HSS has beenshown. Connected in the throw rod conis arranged to operate so as topress the switch either full normal or full reverse depending upon inwhich position it has been placedby the hand switch stand. Any usualdamping or buffer means can be employed in connection with the springmeans if desired. As a result, this spring switch is biased to itsoperating position andcan be moved by a train trailing it to its otherposition.

For example, the switch is shown in its normal position, for main linetraffic, but a train'passing onto the main line from the siding can moveEach track section is supplied with a usual source of energy, such as atrack battery TB, and a track relay TR, each identified with the sectionwith which it is associated by an ex'- ponent corresponding to thesection number. For example, track section I has track battery TB andtrack relay TR Usual interlocked relays XR! and XRZ are employed havingthe usual two separate windings and separate armatures, and with anyusual interlocking means between the armatures such as M and I5. Theseinterlocked relays function. in the usual manner, whereby, upondeenergiza-- tion of relay XRI, for example its armature drops, andmakes up its back point, and moves the lock or hook member l4counterclockwise so as to move into the path of movement of the,

hook l5 of relay XRZ. Upon the deenergizaticn of XRZ prior tov thereenergization of XRI, the armature of XR2 drops,.to move lock l5clockwise until engaged by lock I 4, as shown, and

thus prevent the armature of relayXR2 from making up its back points.The subsequent reenergization of relay XRI' causes the armature thereofto pick up, as shown, but the lock I4 is retained in its latchingposition, and hence, in order to allow relay XRZ to make up its backpoints, it is first necessary to release the latch by energizing thewinding of XRZ and then deenergizing the same. The operation of the interlocked relays as described above is the operation which occurs as aneast bound train passes along the main track. Of course, the reversecycle of operation takes place upon a west bound nection 9 is a springbiasing means in which train passing along the main track.

These relays XRI and XRZ can be of the construction disclosed in theField Patent 1,824,131, granted September 22, 1931.

For protection of highway traflic, signals SI and S2 are provided atopposite sides of the highway H at the intersection, and these signalsare of any usual type either steady or flashing, but are shown heresimply as steady light signals for the purpose of illustration. They arecontrolled by the interlocked relays, where'- by both signals areenergized, so long as either of the interlocked relays is making up itsback points.

Employed in the system for the purpose of warning of a move from thesiding into the main track while a receding train is still occupying thesiding approach section is a stick relay SR which has connected acrossits winding a rectifier 25 7 whereby to make it somewhat slow to releasewhile having quick pick-up characteristics.

Having described the apparatus employed in the system, an understandingof the operation of the system will be best obtained by consideringvarious train movements.

As shown in the drawing a train or car I6 is shown passing eastward andin the west approach section 2, and the various parts of the system areshown in the positions and conditions they have assumed, due to thismovement,

When train l6 entered approach section I, track relay TR released todeenergize interlocked relay XRI and thereby energize the highway signals SI and S2 through contact finger 261 and back point of relay XRI,and a remaining circuit obvious from the drawing. As the train enteredhighway section 3, relay TR. released to maintain the signal energizeduntil the rear end of the train had passed out of highway section 3whereupon interlocked relay XRI picked up through a circuit includingcontact finger III and front point of relay TR and contact finger l8 andfront point of relay TR whereby to deenergize the signals, as should bethe case since the receding train does not endanger highway traiiic.

It can be seen that interlocked relay XRZ, having an energizing circuitincluding contact finger l9 and front point of relay TR and contactfinger l1 and front point of relay 'I'R was deenergized upon the trainentering section 3 at which time relay XRI was deenergized. Hence, eventhough relay XRI subsequently became reenergized, the armature of relayXRZ was latched up as shown in the drawing, and though it isdeenergized, due to the presence of the train in section 2, it cannotmake up its back point, and hence cannot energize the highway signals.

Assume now that a train 20 on the. siding enters the main track insection 2, while train I still occupies section 2, and hence stillmaintains relay XR2 latched up. Unless means he provided for releasingthis latch, the train entering from the siding can approach and passover the highway without having, given any warning to highway traffic. v

As set forth above, after one of the interlocking relays is latched up,and the other relay has become reenergized, in order to release thelatch it is merely necessary to momentarily energize the latched uprelay, in the case in point, relay XRZ, whereby to permit the latchingmeans, as M, of the other interlocked relay, to swing in a clockwisedirection and out of the way.

Upon train 20 passing onto the main track, the

spring switch is trailed and is moved over to its full reverse position,thereby closing track switch operated contact l2 to thus complete acircuit for energizing the interlocked relay XR2, which circuit includescontact finger l1 and front point of relay TR contact finger l9 and backpoint of relay TR switch operated contact l2 in its closed position, andcontact finger 2| and back point of the stick relay SR,

Upon relay XR2 picking up, it closes a circuit for picking up stickrelay SR which pick-up circuit includes contact finger I1 and frontpoint, contact finger l9 and back point, contact finger 22 and frontpoint of relay XRZ, and the winding of relay SR.

The picking up of relay SR opens the energizing circuit for relay XRZ atcontact 2| whereby relay XRZ releases. The releasing of relay XRZ breaksthe pick-up circuit for relay SR, but this relay remains up through astick circuit which includes contact finger l1 and front point, contactfinger l9 and back point, and its own contact fin er 23 and front point.

With the release of the latching and the deenergization of interlockedrelay XRZ, the signals at the highway crossing are energized throughcontact finger 24 and back point of relay XRZ, whereby to give adequatewarning to highway traffic of the approach of the train 20 which isentering the main track from the siding and approaching the highway.

It is obvious that an east bound train instead of proceeding as is trainl6, past the siding, might enter the siding, in which case the trackswitch would be moved by hand to its reverse position to permit thetrain to enter th siding. Unless provision be made against it, thismovement of the switch would cause a display of the highway warningsignals, and thus warn of a danger which would not exist because'thetrain is receding from the highway and thus would cause unnecessarydelay and confusion.

Assume now, with the system all restored to normal, and no trainspresent on the track, that an east bound train passes over the highwayand onto the siding. As the train passes through sections I and 3, thewarning signals are given as described above, until the rear end of thetrain passes out of section 3, whereupon the signals become deenergized.It is also to be assumed that the track switch TS is thrown by hand toreverse position while the train is still occupying section 3.Accordingly, a circuit is completed for picking up stick relay SR whichcircuit includes. contact finger l1 and back point of relay TR and theswitch operated contact IS in its closed position.

It should be noted that, with track relay TR deenergized, the circuitfor energizing the interlocked relay XRZ to release its latching, is notcompleted by movement of the track switch since this circuit included afront point of relay TR Thus, the movement of the switch under thecircumstances outlined cannot eifect an unlocking of the interlockedrelay XR2, and thus the,

stick relay in picked up position and prevent the energization ofinterlocked relay XRZ by maintaining the energizing circuit for it openat contact finger 2!, of the stick relay. Thus, the operation of theswitch to permit th east bound train to enter the siding is preventedfrom causing an unlatching of the interlocked relay XRE, and a resultingunnecessary and confusing highway warning.

It is obvious that, should there be a siding entering the main track inapproach section I, track switch operated contacts and a stick relay andassociated circuits could be employed in connection with interlockedrelay XRI to protect against unnecessary and undesired highway Warningin connection with this siding in the same manner as described above.

The above rather detailed description of one form which this inventioncan assume, has been given solely by way of example, and is not intendedin any manner whatsoever in a limiting r sense. The present applicationcontemplates covering all the various modifications and variations ofstructure and arrangement as may occur from time to time as desirableinsofar as they are not specifically excluded from the scope of thisapplication by the appended claims.

Having described my invention, I now claim:

1. In a signal system for highway-railway crossings, a highway crossinga stretch of main line track, a highway signal at the crossing, apassing siding, a track switch connecting the passing siding to the mainline adjacent the highway, an approach track section at each side of thehighway, a middle track section interconnecting the approach sections,the approach section at the siding side including the track switch, twointerlocked relays, associated, respectively, with the two approachsections, circuit means for displaying the signal and effective wheneither relay makes up its back point, an energizing circuit for eachrelay closed only when its approach sectionv and the middle section isunoccupied, the relays being so interlocked that if one be deenergized,while the other is in deenergized position, the armature of the one islatched up so as to prevent its making up its back point until aftersaid other is reenergized and then said one is reenergized, a stickrelay, a second energizing circuit for the interlocked relay associatedwith the passing siding approach section and including a back point ofthe stick relay, a contact closed upon positioning of the track switchaway from its full normal position and a contact closed only if thepassing siding approach section be occupied, and a pick-up circuit forthe stick relay including a front point of said passing siding approachsection interlocked relay, and the contact closed only if said passingsiding approach section be occupied.

2. In a signal system for highway-railway crossings, a highway crossinga stretch of main line track, a highway signal at the crossing, apassing siding, a track switch connecting the passing siding to the mainline track adjacent the highway, an approach track section at each sideof the highway, the on at the siding side including, at an intermediatepoint, the track switch, a middle section of track interconnecting theapproach sections, two interlocked relays, associated, respectively,with the two approach sections, circuit means for displaying the signaland effective when either relay makes up its back point, an energizingcircuit for each relay closed only when its approach section, and themiddle section, is unoccupied, the relays being so interlooked that ifone be deenergized, while the other is in deenergized position, thearmature of the one is latched against making up its back point untilafter said other is reenergized and then said one is reenergized, astick relay, a second energizing circuit for the interlocked relayassociated with the passing sidin approach section and including a backpoint of the stick relay, a contact closed upon positioning the trackswitch away from its full normal position, a contact closed only if thepassing siding approach section be occupied and a contact closed only ifthe middle section be unoccupied, a pick-up circuit for the stick relayincluding a front point of said passing siding approach sectioninterlocked relay, and the contact closed only if said passing sidingapproach section be occupied, and the contact closed only if the middlesection be unoccupied, and a stick circuit for the stick relay includinga contact finger and front point of the stick relay constituting a shuntacross the front point of said passing siding approach sectioninterlocked relay.

3. In a highway crossing signal system, in combination, a stretch ofmain track crossin a highway, a highway signal at the crossing, anapproach section of track at each side of the highway and eachterminating short of the highway, a common highway section of trackincluding the highway and interconnecting the adjacent ends of theapproach sections, a normally open signal energizing circuit for eachdirection of trafiic, a control means for each energizing circuit andresponsive to track occupancy to close its circuit and energize thesignal so long as its approach section or the commonhighway section isoccupied, a passing siding, atrailable spring track switch, operable toassume either normal or reverse positions and spring biased to its thenoperated position connecting the siding with an intermediate point ofone of the approach sections, interlockin means between the two controlmeans, and normally preventing the occupancy of the approach sidingsection, by a vehicle receding from the crossing after having occupiedthe highway section, from energizing the signal, additiona1 circuitmeans effective, when closed and then opened, to make the interlockingmeans ineffective, means closing the additional circuit means when thetrack switch is trailed away from its full normal position and thesiding approach section is occupied and the highway section isunoccupied and means reopening said additional circuit after saidadditional circuit has been closed.

ARTHUR E. REID.

